Electron-impact single-ionization cross-sections for levels (³P₂, ¹D₂, and ¹S₀) of the ground configuration of the Ar²⁺ ion. DI cross-sections are obtained in the potential of the ionized ion. Experiment: open circles with error bars – Diserens et al. (1988); open triangles with error bars – Man et al. (1993). Dotted line (magenta) – CADW total single-ionization cross-sections (Loch et al. 2007), dash-dash-dotted line (gray) – CADW DI cross-sections (Loch et al. 2007).